Sharp QS 2130 QS-2130 Operation Manual - Page 9

POWER SUPPLY This calculator has a solar cell and is energized by electrical energy produced by the solar cell. The solar cell converts luminous energy directly into electrical energy by utilizing the photovoltaic effect. Brightness for operation If the light exposed to the solar cell is insufficient, the calculator is not powered to operate. With the brightness criterion below, operate the calculator at 150 Iux or more. Outdoors or by the window: Incandescent lamp: Fluorescent lamp: Use the calculator where it is not exposed to direct sunlight but receives enough illumination for comfortable reading. Use the calculator wherever it receives the same illumination as attained within 2.5 meters of a 100 Watts incandescent lamp. Use the calculator wherever it receives the same illumination as attained within 1.5 meters of a 15 Watts fluorescent lamp. Backup Battery If the light exposed to the solar cell is insufficient (150 Iux or lower), the backup battery is turned on automatically to operate the calculator. 8